Construction of validation modules based on reference functional models in a standalone verification of communication subsystem

The paper proposes some approaches to functional verification of microprocessor communication controllers based on developing layered UVM (Universal Verification Methodology) test systems. In modern microprocessor systems there are a lots of controllers operating with their own data types. Communication controllers support transferring and transformation data between microprocessor units. Such transformation must be carried out quickly and without data corruption for the correct functioning of the whole system. Communication controllers could carry additional functions such transmission values of copies of the system registers, address translation and others. Brief overview of verification tools and benefits of application standalone simulation based verification for checking the correctness of communication subsystems are marked out in the paper. We present the approaches of construction a standalone UVM-based verification environment with checking module implemented in external functional reference model. We also propose some techniques for checking the correctness of communication subsystems: checking multiple-clock controllers using parametrized clock generator, supporting of credit exchange mechanisms. Presented approaches were used to verify the communication subsystem - Host-Bridge - of Sparc V9 eight-core microprocessor developed by MCST. The difficulties discovered in the process of test system developing and its resolutions are described in the paper. The results of using presented solutions for verification of communicating subsystem controllers and further plan of the test system enhancement are considered.